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(No Model.) A i J. A. COLEMAN. GRINDING MACHINE.

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No. 376,815. l .2, Patent-ewan. 24, 1,888.

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lJ. A. COLEMAN. f

GRINDING 'MAGHINR Nq. 376,815. nue-d Janqm, 18,88.

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J. A. COLEMAN.

3 .Sheets-#Sheet 3.

(No Model.)

GRINDING MACHINE.

No. 37,6.,815. Patented Jan. 24, 1888.l

UNITED STATES PATENT OFFICE.

JOHN A Vr'coLEMAn, er PROVIDENCE, nnonn IsLANn.

RlNolNG-MACHINE.

SPECIFICATION forming part of Letters Patent No. 376.815. 'dated January 24, 1888.

I Applicatio-1red Apr-i116. lel. Serial No.235.079. (No model.)

4To all whom it muy concern;-

Be it kfown that I, lJOHN A; COLEMAN, of the citynd county of Providence, in the State fof, Rhode Island,haveinvented eertai n new and4 usefulg'lmprovements in Grinding-Machines; and I (lo` rhereby declare. that'n the lfollowing s citl cation,taken in vconnect-ion with the d awings furnished and forming a part of the sarne,lis a clear, true', and complete description 'of the .several features of my invention.

In an applieationfor Letters Patent filed by me lllvay, 23,' A1886, Serial No. 166,434, I diseiosed'certain improvements in grinding-ma-- chines adapted to perform a wide range ofservice, anda characteristic feature in my prior machinesinvolved extensive variations in the position-of the grinding-,surfacewith reference to thework-supporting table; butI' have now devised and organized amachine whereinthe grinding-wheel is eapableof being'varied in position to "meet varied requirements, and

when set in anyone position ,the` worksupporting table can be raised andlowered to and from the grinding-surface, and also rotated for presenting the surface to `beground tov said grinding-surface underwidely varying conditions. j

- A grinding-machine embodying my im provements in their best formpossesses capaeltiesfor performing a greater variety of work than any other lmachineknown to me. After describing my invention as illustrated in the accompanying three sheets of drawings,

the yfeatures deemed novel will be vduly speci- 'ed in the several clauses of claim hereunto annexed.

Referring "to the'drawings, Figure 1 is a front elevation of a'grmding-maehine containingjmy-present improvements'. Fig. 2 illustrates 'the same partially in side view and partially in central vertical section, but with out the auxiliary work-bed shown in Fig. 1.

Fig. 3 is a horizontal lateral section of the e samefshowingthe work-supporting table' in" topview, but without said auxiliary bed. Fig.

p lis a longitudinal vertical section'of the table,

showing adjacent portions of ther frame and means for moving and adjusting the table jin horizontal planes. Fig. 5 is a sectional View of the frame below the table, and shows the table-liftingfscrew and its connections in -a .ively-adjustable at its spindle.

modified form. Fig. 6 illustrates still another modification of the table-lifting mechanism. The frame of the machines includesl a cylindrical vertical base, A, aud a bracket-or shoulder atr b2 on said spindleone or more round or U-shapcd washers, b", are` inserted,

thus enablingthe whcel-frame ll to .be not only adjusted at any desired height but rota- A is constructed lin two sections, the upper part being pivoted uponthe lower part, 'as atr a', the pivot being'a bolt provided with 'a clampnut, ai. l vided at its foot vwith segmental gear, e, which is` engaged by aworm on a eyankshaft, a, thusenabling the upper part of the bracket, with the wheel-frame, to be swung in the-arc of a. circle for locatingl .the grinding-wheel either coincident with the ycenter of the vtable or at any desired point at one'side of the center. v

The grinding-willed C. is mounted in hearings in the lowerrend of` the frame B, and is provided with a band-pulley, c. It will be seenA that the grinding-wheel mounted in its pendent frame has anunobstruetcd periphery below the plane of its axis,

- and hence it is capable of grinding in a vertical plane as well as horizontally, and also that it canbe adjusted for duty'in any' desired position by swiveling on its stem at rightangles to its axis, 4and also that it can be swung bodily to the right hand or the lleft 'because of its swiveledbracket, thus enabling au extraordi-` nary wide range of duty regardless ot' varia- 9 5lv I tions in thevsize and shapeof aforging or cast'-r ingto be operated uponby the grinding' wheel.v f

The interior of the base A is turned out to aiord a truly cylindrical space vfor the rccepvroo tion of the cylindrical shank d ol' the table D,

so that said shank may slide freely, but in a arm, A, extending from the base at-onc side In the top of the bracket A there isa n i Between the lower end of the vhousing' a and a v Said upper part is also pro` 1 v truly vertical line. As shown in Fig. 2, said shank d at its lower end has a disk, e, fixer therein, which is provided with a central hub having a tapped hole at e', which is occupied by a screw, f, stepped in asuitable bearingf', and provided with collars f, by which the screw is restricted to a rotative movement. An inclined crank-shaft, g, projects upward from near the base of said screw and outward through the base, its crank y being at its outer end, and its inner end being geared to the screw by means of the bevelgears g g3. As thus organized, the tableis readily raised and lowered by rotating said crank-shaft. On top of said base A. an annular bearing-surance is afforded for the annular woruigear Ii, which snugly encircles said shank d, and thelattcr is free to slide therein; but the two are locked together against independent rotation by means of a spline, (in the gearJwhich occu-A pies the vertical groove h in one side of said shank, as clearly indicated in Fig. 2. rlhe worm-gear is prevented from rising by means of an ovcrhanging hook, h2, bolted to the outside of the upper portion of the base. A transverse worm shaft, i, provided with a 'handcranlg i', is mounted in suitable bearings and engages with the worm-gear il., as clearly indicated in Fig. 2, it being apparent that by the rotation of said worm-shaft i the table D can be readily rotated.

The' table D is necessarily complex for cnabling its work supporting surface to be moved in various directions in horizontal planes, and hence, as in my prior machines, thc top ofthe table involves tivo sliding tables or beds, l; and l. The lower sliding bed, 7c, is dovctailed at ir to the main portion 1) ol" the table, which may be termed the rotative bed,77 as clearly shown in Fig. I, so to slide to and fro thcein; and the upper sliding table or bed, Z, is mounted upon the table 7.' at right angles thereto, and slides on transverse guides l', as clearly shown in Figs. 2 and 8, thus pro viding for all requisite movements in horizon A tal planes. l

The sliding bed or table 7; is moved lo and fro on its bearings by means of thehaml-scrcw k2, occupying bearings in the table and tapped into a block, lui, pendent from said bed, as shown in Fig. Il, and provided with a crank, k, asshown in Fig. l.

The bed Zis moved to and. fro by means of a. rack-gear, It, on its under side and a gear, l, 0n a shaft, Z, having a crank, l, all as clearly i ndicated.`

The sliding bed 7c is slotted to afford proper space for the gear l, and the latter is spliued upon its shaft, so that it may move laterally to and fro with the bed 7.'.

As thus far described, it is obvious that a rotation of the iablewill also cause it to risc or fall on its liftingscrew if the latter be not also rotated so as to counteract the lifting,

movement. In Fig. 5 I have shown the lifting-screw f, tapped into a globular nut, f, which 1s non-rotative, but nevertheless will admit of some slight variations in the position ot' the screw with reference to the tableshank d, and thus insure free and easy movements of the screw and the shank, even if their axes were not always exactly in line with each other. rlhe disk e in this case is not bolted to the shank d, but its edge is freely confined in an annular bearing 'at e, so that the tableshank can revolve without revolving the disk, the latter being free to rise and fall with the table, but kept from rotating by means of a guide, e", bolted `to the inner side of the base A and projecting upward th rough aguide-hole in said disk. l

For grinding flat, beveled, or concave surfaces in annular lines or uponl annular pieces 'of work the table is rotated and the grindingwheel swung sufficiently away from the center to enable it to occupy the required annular path. A circular auxiliary bed is placed upon the table, as indicated in dotted lines iu Fig.4 3. The sliding bed Iris locked in a truly central position onthe tableD by means of thu rnb-screws 7:5, which accurately register with tapered holes in the underlying portion of the top of the table. rIhe circular auxiliary hed referred tois secured to the table by means of bolts passing through the holes k6 in the sliding bed Z and into tapped holes in the bed 7s, thus providing for securely mounting said circular bed firmly and concentrically on the table, so that with the grinding'wheel properly located and a ring-shaped piece of work properly mounted on the bed the table may be rotated and the piece to be ground presented progressively in annular lines to the griiulingsurlhce. It is sometimes desirable that circular andI toand-fro movements be alternately employed in presenting the same piece of work, in which case the beds k and l are not locked together and to the table, the circular auxiliary bed being then secured to the bed l by means of bolts occupying the tapped holcscirl, this permitting oval work to be well presented to the grindingvsurface, the com plcx table then containing elements essentially involved in an oval chuck. In grinding circular planes or eoncavcs, as when rotating the table, it is generally desirable to employ a grinding-wheel having a rounded vface, so that as the surface to be ground is presented laterally to the wheel the grindingsurface can operate progressively; but if the grinding is to be executed in circular lines a flat-faced grimling-wheel is preferably employed.

When my machines are desired mainly for performing such duties as will involve the rotation of the table during the grinding opcration, I specially provide for said rotative movenient at the lifting and supporting mechanism.

.lhearran ementof the screw its ta ),and disk as shown in Fig. 5, is of special value in this connection; but a still greater freedom for rotative movement is provided for in the arrangement illustrated in Fig. G, wherein the rota tivcscrew f rises and descends in its tapped bearingf, which is secured to the interior of nally grooved, and a worm-gear, g4, is splined .thereto and rotated by means of a worm on a be properly mounted. The cam crank-shaft, g5, so that the table can be easily raised and lowered. I he gear g* is supported on a suitable bearing, which also serves' as a vertical guide for the screw. Vithl my machine I also employ for performing certain kinds of work a loni1.udi nally tilting- Work-supporting frame, E, as an auxiliary bed, which is pivoted at one end, as at m, to the bed Z, and `at the opposite end is provided with an adjusting supporting-cam, n, vwhich is rotated by means of aworm-gear and shaft, n. This auxiliary bed is provided with suitable adjusting-centers, as ato, thus enabling axial or cylindricaly pieces of work to will permit said auxiliary bed to occupy a horizontal position for straight cylindrical work or an inelined position for tapered work, as indicated in Fig. 1, 'and this latter adjustment is desirable not only lfor round tapered work, but also for tapered polygonal work, each variety in-v -vffwin-g merely a change in the relative positions of the surface to be ground and the grindingwhee1as, for instance, in Fig. l the auxiliary bed and grinding-wheel are set for grinding a flat-surfaced taper or wedge; but if the taper is lto be round the table would be'rotated ninety degrees,;so that the axis ofthe grinding-wheel would be parallel with the axis of the piece to be ground.

In my said prior application if or Letters Patent certain features of invention were disclosed which have been embodied in my present machine, and certain of the-features ofconstruction and-arrangement heretofore employed by me can be applied to my present machines. without departurefrom certain portions of my present invention. l .A

Having thus described my invention, I claim as new and desi reto secu re by Letters Patentl. In a grinding-machine, the combination,

substantially as hereinbef re table is mounted, a' pendent grinding-wheel' for varying the space between tati ve bed sliding workftable, an overhanging grinding# wheel supported in a pendent p'ivoted frame, by means of which the wheel has-'an unobstructed periphery and is. pivoted at right angies toits axis, andm'eans' for-lifting and l'ow the combination, 4

ering said table and maintaining it in positiv/n. 2. In a grinding-machine, substantially as hereinbefore' described, o f-a desoribedy'f..

sliding work-supporting table which isl nonrotative in itself, a rotative bed on which said abovesa'iil 4work-supportingy table, and means the grinding-face of said wheel and the table. 3. In a grinding-machine, the combination, substantiallyas hereinbefore described, of a rotative bed, -a'worksupporting table non-rotative in itself, but fitted to a transverse slide von said bed, a pendent grinding-wheel mountedin bearings above said table and supportedby a suitable bracket, and means for raising and lowering said bed ,and :maintaining itin postion. 4. Ina grinding-machine, the'combination, substantiallyas hereinbefore described,of a rotative bed, a work-table nonrotative in itself, but fitted to a transverse slide on a sec-v ond sliding table interposed between' saidropendent grinding-wheel mounted in bearings u above the work-supporting table, and means' for raising and lowering said' bed and tables and maintaining themin position;:f" v 5. In a gri ding-machine, the combination,

substantially as hereinbe'fore described, of the grinding-wheel, the lsliding table beneath said b5 v wheel, means -for varying the space between 'the grinding-face of said wheel and the table,

and a longitudinally-tilting work-supporting frame mounted u-ponjsaid sliding table and WILLIAM MOLLoY, VFRANK W. ALLIN.

supported at vone end byanadjustinglcam ro- 9o 

